Hot-Carrier Effect on Amorphous In-Ga-Zn-O Thin-Film Transistors With a Via-Contact Structure

The effect of hot carriers on the characteristics of via-contact-type amorphous In-Ga-Zn-O thin-film transistors is investigated. After hot-carrier stress, the gate-to-source capacitance curve shows a two-stage rise while the gate-to-drain capacitance curve exhibits parallel shifts. It is found that hot electrons are injected into the etch-stop layer or trapped at the InGaZnO/etch-stop layer interface below redundant drain electrode. This is further verified by measuring the characteristic capacitance curve with a positive top gate bias.